net/sfc: remove unnecessary mbuf initialization on Rx

mbuf next is equal to NULL, nb_segs and reference counter are equal to 1
when mbuf is obtained from mempool.

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

diff --git a/drivers/net/sfc/sfc_ef10_rx.c b/drivers/net/sfc/sfc_ef10_rx.c
index 2a3bf89..1484bab 100644 (file)
--- a/drivers/net/sfc/sfc_ef10_rx.c
+++ b/drivers/net/sfc/sfc_ef10_rx.c
@@ -386,9 +386,8 @@ sfc_ef10_rx_process_event(struct sfc_ef10_rxq *rxq, efx_qword_t rx_ev,
 
        *rx_pkts++ = m;
 
-       *(uint64_t *)(&m->rearm_data) = rxq->rearm_data;
-       /* rearm_data rewrites ol_flags which is updated below */
-       rte_compiler_barrier();
+       RTE_BUILD_BUG_ON(sizeof(m->rearm_data[0]) != sizeof(rxq->rearm_data));
+       m->rearm_data[0] = rxq->rearm_data;
 
        /* Classify packet based on Rx event */
        sfc_ef10_rx_ev_to_offloads(rxq, rx_ev, m);
@@ -412,7 +411,7 @@ sfc_ef10_rx_process_event(struct sfc_ef10_rxq *rxq, efx_qword_t rx_ev,
        rte_pktmbuf_data_len(m) = pkt_len;
        rte_pktmbuf_pkt_len(m) = pkt_len;
 
-       m->next = NULL;
+       SFC_ASSERT(m->next == NULL);
 
        /* Remember mbuf to copy offload flags and packet type from */
        m0 = m;
@@ -426,9 +425,9 @@ sfc_ef10_rx_process_event(struct sfc_ef10_rxq *rxq, efx_qword_t rx_ev,
                if (ready > rxq->prepared)
                        *rx_pkts++ = m;
 
-               *(uint64_t *)(&m->rearm_data) = rxq->rearm_data;
-               /* rearm_data rewrites ol_flags which is updated below */
-               rte_compiler_barrier();
+               RTE_BUILD_BUG_ON(sizeof(m->rearm_data[0]) !=
+                                sizeof(rxq->rearm_data));
+               m->rearm_data[0] = rxq->rearm_data;
 
                /* Event-dependent information is the same */
                m->ol_flags = m0->ol_flags;
@@ -449,7 +448,7 @@ sfc_ef10_rx_process_event(struct sfc_ef10_rxq *rxq, efx_qword_t rx_ev,
                rte_pktmbuf_data_len(m) = pkt_len;
                rte_pktmbuf_pkt_len(m) = pkt_len;
 
-               m->next = NULL;
+               SFC_ASSERT(m->next == NULL);
        }
 
        return n_rx_pkts;
@@ -560,7 +559,8 @@ sfc_ef10_mk_mbuf_rearm_data(uint16_t port_id, uint16_t prefix_size)
 
        /* rearm_data covers structure members filled in above */
        rte_compiler_barrier();
-       return *(uint64_t *)(&m.rearm_data);
+       RTE_BUILD_BUG_ON(sizeof(m.rearm_data[0]) != sizeof(uint64_t));
+       return m.rearm_data[0];
 }
 
 static sfc_dp_rx_qcreate_t sfc_ef10_rx_qcreate;

diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
index 56130b2..ddf9217 100644 (file)
--- a/drivers/net/sfc/sfc_rx.c
+++ b/drivers/net/sfc/sfc_rx.c
@@ -122,10 +122,10 @@ sfc_efx_rx_qrefill(struct sfc_efx_rxq *rxq)
                        rxd = &rxq->sw_desc[id];
                        rxd->mbuf = m;
 
-                       rte_mbuf_refcnt_set(m, 1);
+                       SFC_ASSERT(rte_mbuf_refcnt_read(m) == 1);
                        m->data_off = RTE_PKTMBUF_HEADROOM;
-                       m->next = NULL;
-                       m->nb_segs = 1;
+                       SFC_ASSERT(m->next == NULL);
+                       SFC_ASSERT(m->nb_segs == 1);
                        m->port = port_id;
 
                        addr[i] = rte_pktmbuf_mtophys(m);